The energy consumption can be reduced significantly if efficient heating systems are used and if the interaction between the building and the heating installation is optimized.

National building codes will evaluate the quality of the building and the heating system in a system approach, taking into account the interaction.

European standardization identified the need for a reliable method for calculation of the energy performance. The work concerning the heating system is done by CEN TC 228 (heating systems in buildings)WG4 (calculation methods).

Standard prEN 14 35, Method for Calculation of System Energy Requirements and System Efficiencies, takes into account the losses of emission, distribution, storage, heat generation, and control. The energy requirements are converted to primary energy. The basis of the calculation of these losses is the building heat use determined according to prEN 13 790, Calculation of Energy Use for Heating.

This integrated methodology could be the basis for energy performance standards adopted by the European Member States.

If no European method is available, there is a risk that the specifications of national building codes will become new trading barriers for products throughout Europe.

Units: SI